JP2016057386A - Image tremor correction device and optical device having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image tremor correction device and optical device including the image tremor correction device that allow electromagnet actuators to be compactly packed in one area for actuating in two axial directions, and allow the electromagnetic actuators to be downsized without causing magnetic interference.SOLUTION: An image tremor correction has: a movable frame that holds an optical element or photoelectric conversion element; a magnet member which is made integral with the movable frame, and in which first and second magnetic pole faces including a normal vector parallel with an optical axis have one pole magnetized, respectively; a first actuator coil that is fixedly arranged opposing the first magnetic pole;n and a second actuator coil that is fixedly arranged opposing the second magnetic pole. In order to curb an image tremor, electrification to the first actuator causes the movable frame to move in a first direction in an in-plane orthogonal to the optical axis, and electrification to the second actuator coil causes the movable frame to move in a second direction orthogonal to the first direction in the in-plane orthogonal to the optical axis.SELECTED DRAWING: Figure 1

Description

  The present invention moves an optical element such as a lens or a photoelectric conversion element such as an imaging element by using an electromagnetic force acting between a coil and a magnet in order to suppress (correct) image blur caused by camera shake or the like. The present invention relates to an image blur correction apparatus and an optical apparatus having the same.

  An image stabilization device (anti-vibration unit) mounted on a camera or interchangeable lens detects camera shake and other vibrations, and moves (decenters) the lens in a direction perpendicular to the optical axis according to the detection result. There is.

  In the image blur correction device described in Patent Document 1, an electromagnetic actuator is configured by a coil and a magnet, and an electromagnetic force generated between the coil and the magnet by energizing the coil is used to move the lens in two orthogonal axes ( (Pitch and yaw direction).

  Furthermore, in the image blur correction device described in Patent Document 2, electromagnetic actuators for driving a driving object such as a lens in two axial directions can be arranged in a compact area in one area.

JP-A-11-305277 JP 2008-125263 A

  However, in the prior art disclosed in the above-mentioned Patent Document 2, when the magnet is rotated 90 degrees on the front surface (object side) and back surface (image side) of one magnet, or the two magnets are rotated 90 degrees. When bonded together, the magnetization phases of the front surface and the back surface are shifted by 90 degrees. For this reason, relative magnetic interference between the front and back surfaces may occur, and the driving force may not be generated as expected, and it is necessary to design a larger actuator to improve the loss of the driving force. It was.

  An object of the present invention is to compactly combine electromagnetic actuators for driving in two axial directions into one area, and to reduce the size of the electromagnetic actuator without causing magnetic interference, and an optical having the same To provide equipment.

  In order to achieve the above object, an image blur correction apparatus according to the present invention includes a movable frame that holds an optical element or a photoelectric conversion element, and a normal vector that is integrated with the movable frame and is parallel to the optical axis. The first and second magnetic pole surfaces provided with a magnet member each magnetized by one pole, the first drive coil fixedly arranged facing the first magnetic pole surface, and the second magnetic pole surface opposed And a second drive coil fixedly arranged, and in order to suppress image blurring, the first drive coil is energized in the first direction in a plane orthogonal to the optical axis. The movable frame is moved, and the movable frame is moved in a second direction orthogonal to the first direction within a plane orthogonal to the optical axis by energizing the second drive coil. .

  An optical apparatus according to the present invention includes the image blur correction device.

  According to the present invention, the electromagnetic actuator for driving in the two-axis directions is compactly integrated into one region, and the image blur correction apparatus capable of reducing the size of the electromagnetic actuator without causing magnetic interference, and the optical having the same Equipment can be provided.

It is sectional drawing of the lens-barrel which mounts the image blurring correction apparatus which concerns on embodiment of this invention. 1 is a perspective view of a video camera equipped with an image blur correction device according to an embodiment of the present invention. (A) is a sectional view of an actuator part in the image blur correction device according to the embodiment of the present invention, and (B) is a view of the image blur correction device as viewed from the image plane side. 1 is a perspective view of an image blur correction apparatus according to an embodiment of the present invention. 1 is an exploded perspective view of an image blur correction device according to an embodiment of the present invention. It is the perspective view which looked at the movable part and four guide bars of the image blur correction device according to the embodiment of the present invention from the object side. It is a figure which shows the electrical constitution of the camera carrying the image blurring correction apparatus which concerns on embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<< First Embodiment >>
(Lens barrel and imaging device as optical equipment)
FIG. 2 is a perspective view of a lens barrel (FIG. 1) as an optical apparatus having an image blur correction apparatus (anti-vibration unit) according to an embodiment of the present invention and a video camera as an image pickup apparatus that is an optical apparatus having the lens barrel. FIG. In FIG. 2, L is a lens barrel and B is a camera body. The image blur correction device (anti-vibration unit) according to the embodiment of the present invention can be mounted not only on a video camera but also on various optical devices such as an imaging device such as a digital still camera and an interchangeable lens.

  In FIG. 1, L1 to L4 are first to fourth lens units disposed on the optical axis AXL in order from the object side to the image side. Reference numeral 1 denotes a first group barrel that holds the first lens unit L1, and reference numeral 2 denotes a V moving ring that holds the second lens unit L2 and moves in the optical axis direction to change the magnification. Reference numeral 3 denotes a light amount adjustment unit that adjusts the amount of light so that an appropriate amount of light is incident on the image sensor 20. The first to fourth lens units L1 to L4 and the light amount adjustment unit 3 constitute a photographing optical system (imaging optical system).

  Further, parts other than the actuators of the V moving ring 2 and the light amount adjusting unit 3 are arranged in the first group barrel 1. Reference numeral 5 denotes a shift base barrel fixed as a fixed frame that is fixed between the first group barrel 1 and a mount barrel described later and supports a shift barrel 9 that is a movable frame described later. Reference numeral 13 denotes a fixed lens barrel fixed between the first group lens barrel 1 and the shift base lens barrel 5.

  Reference numeral 14 denotes a mount lens barrel that holds the image pickup device 20 and covers a portion other than the shift base lens barrel 5 and a focus lens barrel, which will be described later, in the image stabilization unit. The imaging element 20 is a photoelectric conversion element such as a CCD sensor or a CMOS sensor.

  Reference numeral 15 denotes a focus barrel that holds the fourth lens unit L4 and moves in the optical axis direction to perform focusing. Reference numeral 21 denotes an optical filter such as an infrared cut and a low-pass filter held between the fourth lens unit L4 and the image sensor 20 in the mount barrel 14.

(Image blur correction device)
Next, the image stabilization unit as the image blur correction apparatus according to the embodiment of the present invention will be described in detail with reference to FIGS. Here, FIG. 3 (B) is a view of the image stabilization unit viewed from the image plane side, and FIG. 3 (A) is a cross-section of the actuator portion therein (cross-section AA). 4 is a perspective view of the vibration isolation unit, FIG. 5 is an exploded perspective view of the vibration isolation unit, and FIG. 6 is a perspective view of the movable portion of the vibration isolation unit and four guide bars as viewed from the object side.

  In FIG. 3A, reference numeral 4 denotes a first drive yoke that is fixedly held by the shift base barrel 5 and passes through the winding axis of the first drive coil inside the winding of the first drive coil 6. It is. The first drive coil 6 is also fixedly disposed on the shift base barrel 5. The first drive coil 6 is wound in the shape of a mouth and has four sides as components, but the first drive coil 6 has a first orthogonal plane orthogonal to the AYL direction (FIG. 5) described later as in this embodiment. When wound in-plane, only one side of the four sides faces each other when viewed from the optical axis direction. According to this configuration, the first drive coil 6 can be made smaller.

  Reference numeral 7 denotes a hall element as a first position detection element (position sensor) for detecting movement (position) in the pitch direction P, which is a first direction of a drive magnet, which will be described later. The Hall element 7 is fixed to the shift base barrel 5 after being soldered to a flexible printed circuit board (not shown).

  In FIG. 5, the first drive yoke 4, the first drive coil 6, and the first Hall element 7 are all optical axes from the direction perpendicular to the optical axis AXL (AYL direction in FIG. 5). Assemble toward the center. One of the reasons why the assembly direction becomes this is in the winding direction of the first drive coil 6.

  That is, the first drive coil 6 is wound in a plane perpendicular to the AYL direction in FIG. 5 (in a plane parallel to a plane formed by each vector in the optical axis AXL and the AZL direction described later). Yes. Therefore, the first drive coil 6 is formed with a hole (opening formed by four sides of the mouth shape) penetrating in the AYL direction, and the hole portion is inserted into the shift base barrel 5 so as to adhere or the like. In order to fix by the method, the assembly direction of the first drive coil 6 described above is determined.

  Reference numeral 8 denotes a drive magnet (magnet member). In the drive magnet 8, either the front surface (object-side surface) that is the first magnetic pole surface having a normal vector parallel to the optical axis or the back surface (image-side surface) that is the second surface is one of the surfaces. Is poled so that the other surface is an S pole and the other surface is an S pole.

  Reference numeral 9 denotes a shift barrel serving as a movable frame disposed on the image side of the shift base barrel 5, and holds the drive magnet 8 and the third lens unit (optical element) L3, and the optical axis AXL of the photographing optical system. To correct the image blur caused by the camera shake (suppress). In the image blur correction device (anti-vibration unit) according to the present embodiment, the moving direction of the optical element that is the driving target is not limited to the optical axis orthogonal direction, and may be any direction different from the optical axis direction.

  Reference numeral 12 denotes a second drive yoke that is fixedly held by the shift base barrel 5 and penetrates the winding axis of the second coil inside the winding of the second drive coil 10. Similarly, the second drive coil 10 is fixedly disposed on the shift base barrel 5. The second drive coil 10 is wound in the shape of a mouth, and four sides are constituent elements, but in the plane of the second orthogonal plane orthogonal to the AZL direction (FIG. 5) as in this embodiment. When wound, only one side of the four sides faces each other when viewed from the optical axis direction. According to this configuration, the second drive coil 10 can be made smaller.

  Reference numeral 11 denotes a hall element as a second position detection element (position sensor) for detecting the movement (position) of the drive magnet 8 in the yaw direction, which is the second direction, and is soldered to a flexible printed board (not shown). Then, it is fixed to the shift base barrel 5.

  In FIG. 5, the second drive yoke 12, the second drive coil 10, and the first Hall element 11 are all in a direction perpendicular to the optical axis AXL and in the direction of AYL. Are assembled from the vertical direction (AZL direction in FIG. 5) toward the center of the optical axis.

  The first drive yoke 4 and the second drive yoke 12 are assembled from different directions, but finally contact each other at the connecting portion 4a as shown in FIG. The magnetic path of the magnetic field is configured to be closed.

  One of the reasons why the assembly direction becomes this is in the winding direction of the second drive coil 10. That is, in FIG. 5, the second drive coil 10 is wound in a plane perpendicular to the AZL direction (in a plane parallel to the plane formed by the optical axis AXL and the respective vectors in the AYL direction). ing. Therefore, the second drive coil 10 is formed with a hole (opening constituted by four sides of the mouth shape) penetrating in the AZL direction, and the hole portion is inserted into the shift base barrel 5 to bond or the like. In order to fix by the method, the assembly direction of the second drive coil 10 described above is determined.

  Here, as described above, since the winding surfaces of the first drive coil 6 and the second drive coil 10 are rotated by 90 degrees, as a result, the insertion direction of each drive coil is also rotated by 90 degrees. It has become.

  Now, the second reason for making the assembly direction as described above is cost reduction. In FIG. 5, 5 a is a protruding portion for holding the first drive yoke 4, the first drive coil 6, and the first Hall element 7, and 5 b is the second drive yoke 12 and the second drive coil. 10, a protruding portion for holding the second Hall element 11. The protrusions 5a and 5b are part of the shift base barrel 5. When the insertion directions of the two drive coils are rotated by 90 degrees, the holding portions can be integrated. And a configuration that leads to cost reduction.

  Reference numerals 16a and 16b denote guide bars for guiding the third lens unit L3 to freely move in a plane orthogonal to the optical axis while determining the position of the third lens unit L3 in the optical axis direction. The guide bars 16a and 16b are fixed to the shift base barrel 5 and slide in U-groove portions 9a, 9b and 9c (FIG. 6) existing in three places in the shift barrel 9. The guide bar 16a is fitted to the U groove portions 9a and 9b of the shift barrel 9, and the guide bar 16b is fitted to the shift barrel U groove portion 9c. As described above, there are three U-groove portions, and the surface is determined by these three portions, so the position of the third lens unit L3 in the optical axis direction and the tilting direction (displacement direction) are determined.

  Here, the arrangement position of at least one of the three guide bars (guide bar 16b) is determined by removing a mold that forms a space formed between the projections 5a and 5b in the shift base barrel 5. It exists on the opposite side to the direction (FIG. 3B, FIG. 6). This is because, as described above, the protrusions 5a and 5b are made of one component in order to achieve cost reduction.

  The arrangement positions of the guide bars 16a and 16b (FIG. 3B) are important arrangements for determining the position of the third lens unit in the optical axis direction, and the positions of the surfaces determined by three places are further away from the optical axis center. The accuracy can be increased. In this configuration, as described above, the guide bar 16b is disposed on the opposite side to the mold drawing direction that forms the space formed between the protrusions 5a and 5b. As a result, the protrusions 5a and 5b are made of the same member (one component) while the guide bar is arranged on the outer side with respect to the optical axis, so that an optimal layout configuration is achieved to achieve cost reduction. .

  Reference numerals 16c and 16d (FIG. 3B) denote guide bars for restricting the movement of the third lens unit L3 when it is movable in a plane perpendicular to the optical axis AXL. The shift barrel 9 is linearly driven in the pitch direction which is the first direction, but swings around the guide bar 16c in the yaw direction which is the second direction perpendicular to the first direction. Driven.

  The guide bar 16d is a part for regulating the maximum movement amount of the shift barrel 9. The guide bar 16d is press-fitted or bonded to the shift base barrel 5 with a clearance set in the through hole 9a formed in the shift barrel 9 so that it does not hit within the normal use range. It is fixed by the method of etc.

  Shift base barrel 5, drive yokes 4, 12, drive coils 6, 10, drive magnet 8, shift barrel 9, third lens unit L3, Hall elements 7, 11, four shift guide bars 16a, 16b, The anti-vibration unit is configured by 16c and 16d.

  In this image stabilization unit (image blur correction device), the first magnet is positioned between the first drive yoke 4 and the drive magnet 8 at a position facing the magnetic pole surface on the object side of the drive magnet 8 magnetized with one pole. It arrange | positions so that a part of winding of the drive coil 6 may start. When a voltage is applied to the first drive coil 6 as described above, the pitch direction P that is the first direction between the first drive coil 6 and the drive magnet 8 (FIGS. 3B and 5). Driving force is generated. This driving force is controlled by the magnitude and direction (polarity) of the voltage applied to the first driving coil 6.

  Since the first drive coil 6 is fixed to the shift base barrel 5, the shift barrel 9 as a movable frame and the first as an optical element together with the drive magnet 8 that receives the driving force in the pitch direction P. The three lens unit L3 moves in the pitch direction P.

  On the other hand, between the second drive yoke 12 and the drive magnet 8, a part of the winding of the second drive coil 10 is located at a position facing the one-pole magnetized image side surface of the drive magnet 8. It arrange | positions in this way. When a voltage is applied to the second drive coil 10 as described above, the winding surface of the second drive coil 10 is rotated 90 degrees with respect to the first drive coil 6 as described above. Therefore, a driving force in the yaw direction Y (FIG. 3B, FIG. 5) is generated between the second drive coil 10 and the drive magnet 8. This driving force is controlled by the magnitude and direction (polarity) of the voltage applied to the second driving coil 10.

  Since the second drive coil 10 is fixed to the shift base barrel 5, the shift barrel 9 as a movable frame and the third lens as an optical element together with the drive magnet 8 that has received a driving force in the yaw direction Y. The unit L3 moves in the yaw direction Y.

  When the drive magnet 8 in which the first magnetic pole surface on the object side and the second magnetic pole surface on the image side are each magnetized to move to one pole, the first and second Hall elements 7 and 11 are respectively pitched. An electric signal corresponding to a change in magnetic flux in the direction P and the yaw direction Y is output. Here, the first and second Hall elements 7 and 11 are opposed to the first magnetic pole surface on the object side and the second magnetic pole surface on the image side of the drive magnet 8, and the end portions of the drive magnet 8. Placed in.

  Based on the electrical signals from the first and second Hall elements 7 and 11, it is possible to detect a change in the position of the shift barrel 9 in the pitch direction P and the yaw direction Y, whereby the shift barrel 9 Can be detected two-dimensionally.

  FIG. 7 shows an electrical configuration of a video camera equipped with the image blur correction device (anti-vibration unit) of this embodiment. The output signal from the image sensor 20 is subjected to various signal processing by the camera signal processing circuit 40 and converted into a video signal. The video signal is displayed on a display (not shown) through a microcomputer 41 or recorded on a recording medium (semiconductor memory, optical disk, hard disk, magnetic tape, etc.) (not shown).

  The microcomputer 41 receives signals from the zoom reset circuit 42 that detects the reference position of the second lens unit L2 and the focus position detection circuit 43 that detects the position of the fourth lens unit L4. Then, the zoom motor drive circuit 44 and the focus drive circuit 45 are controlled with reference to these signals to perform zoom drive and focus drive. Further, the microcomputer 41 controls the diaphragm unit drive circuit 46 based on the luminance signal component of the video signal, and changes the aperture diameter of the diaphragm 30 of the light quantity adjustment unit 3 to a size corresponding to the appropriate light quantity.

  Further, the microcomputer 41 receives pitch and yaw shake signals 47 and 48 such as a vibration gyro mounted on the video camera, and based on the shake signals, the pitch of the shift barrel 9 and the target in the yaw direction are detected. The drive position is calculated. Further, the microcomputer 41 receives information on the position (detection position) of the shift barrel 9 from the pitch position and yaw position detection circuits 49 and 50 including the first and second Hall elements 7 and 11, respectively.

  The energization of the first and second drive coils 6 and 10 is controlled through the pitch and yaw coil drive circuits 51 and 52 so that the detection position reaches the target drive position. As a result, image blur correction (anti-shake) is performed.

  As can be seen from FIG. 2 and the like, in the vibration isolation unit of the present embodiment, the electromagnetic actuator that drives the shift barrel 9 in the pitch and yaw directions includes two drive yokes 4 and 12, two drive coils 6 and 10, And the drive magnet 8. That is, the drive magnet 8 is shared by the pitch direction drive and the yaw direction drive. Thereby, compared with the case where two electromagnetic actuators each having a drive coil and a magnet are used as in the prior art, the number of parts is reduced, and the ease of assembly and cost reduction can be achieved.

  Furthermore, the magnet generally has a heavy weight with respect to the size, which is disadvantageous for driving the shift barrel in the so-called moving magnet type vibration isolation unit as in this embodiment. However, in this embodiment, since only one drive magnet 8 needs to be mounted on the shift barrel 9 for biaxial driving, the weight supported by the shift barrel can be reduced. Therefore, it is possible to perform anti-vibration driving at high speed and high accuracy.

  Further, when the vibration isolation unit IS is viewed from the optical axis direction (the direction in which light passes), the two drive yokes 4 and 12, the two drive coils 6 and 10, and the drive magnet 8 include the vibration isolation unit IS. It is arranged in the upper area of. The magnet is a drive magnet in which the object-side magnetic pole surface and the image-side magnetic pole surface are each magnetized to one pole.

  As a result, there is no magnetic interference between the front and back compared to the conventional case where the magnets magnetized with two poles are shifted 90 degrees between the back and front, so there is no loss of driving force and smaller electromagnetic Actuators can be designed. And as mentioned above, the drive coils 6 and 12 can be made smaller by being wound in the planes orthogonal to the AYL direction and the AZL direction in FIG. The video camera can be downsized.

(Modification)
Although the preferred embodiments of the present invention have been described in the above-described embodiments, the present invention is not limited to these embodiments, and various modifications are possible within the scope of the gist.

(Modification 1)
In the above-described embodiment, the configuration example of the image stabilization unit in which the optical glass (optical lens) as the optical element is eccentric is shown. However, the driving target is not the optical element, but a photoelectric conversion element such as a CCD or CMOS sensor. It may be replaced with (imaging device).

(Modification 2)
In the above-described embodiment, the yoke member for closing the magnetic flux and the hall element as the position detection element are used. However, at least one of them can be omitted or replaced with another member.

(Modification 3)
Further, in the above-described embodiment, the lens barrel and the video camera in which the image blur correction device is mounted are shown as the optical apparatus, but the interchangeable lens and the image blur correction device in which the image blur correction device is mounted are mounted. An imaging apparatus such as a digital still camera may be used.

6 .. First drive coil, 8... Drive magnet, 9 .. Shift lens barrel (movable frame), 10 .. 2nd drive coil, 20 .. Image sensor, L 3.

Claims (10)

A movable frame for holding an optical element or a photoelectric conversion element;
A magnet member integrated with the movable frame and having a normal vector parallel to the optical axis and each of the first and second magnetic pole faces magnetized by one pole;
A first drive coil fixedly disposed opposite to the first magnetic pole surface;
A second drive coil fixedly disposed opposite to the second magnetic pole surface;
Have
In order to suppress image blur, the movable frame is moved in a first direction within a plane orthogonal to the optical axis by energization of the first drive coil,
An image blur correction apparatus, wherein the movable frame is moved in a second direction orthogonal to the first direction in a plane orthogonal to the optical axis by energizing the second drive coil. A first position detecting element fixedly disposed opposite to the first magnetic pole surface;
A second position detecting element fixedly disposed opposite to the second magnetic pole surface;
The image blur correction apparatus according to claim 1, wherein: The first drive coil is wound in a plane of a first orthogonal plane orthogonal to the first magnetic pole surface,
The second drive coil is wound in a plane of a second orthogonal plane orthogonal to the first magnetic pole surface and also orthogonal to the first orthogonal surface. The image blur correction device according to claim 1 or 2. A first yoke member is disposed inside the winding of the first drive coil so as to penetrate the winding shaft of the first drive coil,
A second yoke member is disposed inside the winding of the second drive coil so as to penetrate the winding axis of the second drive coil,
The image blur correction apparatus according to claim 3, wherein the first and second yoke members form a closed magnetic path in contact with each other. In the fixed frame that movably supports the movable frame,
5. The device according to claim 1, wherein a first protrusion that holds the first drive coil and a second protrusion that holds the second drive coil are provided. 6. Image blur correction device.   The fixed frame has at least three locations for supporting the movable frame in the optical axis direction, and at least one of them forms a space between the first projection and the second projection. The image blur correction device according to claim 5, wherein the image blur correction device is disposed on a side opposite to a direction in which the mold to be drawn is removed.   An optical apparatus comprising the image blur correction device according to claim 1.   The optical apparatus according to claim 7, wherein the optical apparatus is a lens barrel having the image blur correction device.   The optical apparatus according to claim 7, wherein the optical apparatus is an interchangeable lens having the image blur correction device.   The optical apparatus according to claim 7, wherein the optical apparatus is an imaging apparatus including the image blur correction apparatus.